The Sun Cluster software supplies a set of service management methods. These methods run under the control of the Resource Group Manager (RGM), which uses them to start, stop, and monitor the application on the cluster nodes. These methods, along with the cluster framework software and multihost devices, enable applications to become failover or scalable data services.
The RGM also manages resources in the cluster, including instances of an application and network resources (logical hostnames and shared addresses).
In addition to Sun Cluster software-supplied methods, the Sun Cluster system also supplies an API and several data service development tools. These tools enable application developers to develop the data service methods needed to make other applications run as highly available data services with the Sun Cluster software.